Print Driver Isolation Registry Locations in Windows

Print driver isolation enhances system stability by executing printer drivers in dedicated host processes outside the main Print Spooler process. This article details the exact Windows Registry paths where driver isolation settings, compatibility flags, and host process behaviors are cataloged, along with the specific values used to configure them.

Primary Registry Keys for Driver Isolation

Driver isolation configurations are stored under the primary Print control key in the Windows Registry. You can locate and modify these settings in the following paths using regedit.exe:

1. Per-Printer Isolation Configuration

To view or configure the isolation mode assigned to a specific printer queue:

• Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Printers\<PrinterName>
• Value Name: PrinterDriverIsolation
• Data Type: REG_DWORD

The value assigned to PrinterDriverIsolation dictates how the driver runs: * 0 (None): The driver runs inside the primary Print Spooler process (spoolsv.exe). * 1 (Shared): The driver runs inside a shared isolation host process (PrintIsolationHost.exe) alongside other shared drivers. * 2 (Isolated): The driver runs in its own dedicated, completely separate PrintIsolationHost.exe process.

2. Driver Capabilities and Flags

The Print Spooler checks whether a driver officially supports isolation modes by querying its installed driver catalog:

• Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Environments\<Architecture>\Drivers\<Version>\<DriverName> (Example architecture: Windows x64; Example version: Version-3 or Version-4)
• Value Name: PrinterDriverAttributes
• Data Type: REG_DWORD

A bitmask within PrinterDriverAttributes defines driver capability. If the 0x00000001 (PRINTER_DRIVER_PACKAGE_AWARE) or 0x00000002 flag is present, the driver declares compatibility with isolated execution.

The Print Isolation Host Process

When isolation is configured via the registry, Windows routes driver calls away from spoolsv.exe to:

• Process Name: PrintIsolationHost.exe
• File Location: %SystemRoot%\System32\PrintIsolationHost.exe

If a driver crashes in Shared or Isolated mode, only the corresponding PrintIsolationHost.exe process terminates, leaving the core Print Spooler service active and uninterrupted for other print operations.